This invention relates generally to automatic-transmission automobiles, and more particularly to an anti-creep device therefor.
State and Federal laws (Motor Vehicle Safety Standard No. 105, for example) require that passenger automobiles be equipped with brakes such as a hydraulic service brake system, including an emergency brake system with a red failure warning light, and a friction-type mechanical parking brake system. Many state laws also specify use of such brakes, such as requiring use of parking brakes on hills, etc.
As is well known, when an automatic transmission passenger car, for example, is braked to a stop, as at a stop sign or traffic light, and the operator's feet are removed from the brake and accelerator pedals, the vehicle tends to creep forward, which is an annoying occurrence, if not actually a dangerous one.
By a private poll of one hundred (100) automobile owners, it was determined that 95% of such owners have automatic transmission vehicles and that 85% of them do not use the parking brake. One reason for not using the mechanical parking brake in northern climates may be that they tend to freeze up in the wintertime. This sometimes happens to the extent and at a time that the brake may, in fact, have to be damaged or ruined to free the vehicle. Once that is done, it is unlikely that the brake will be repaired, unless the state has an annual safety check, for example. Another reason that parking brakes are not used may be to eliminate the possibility of subsequently driving the vehicle with the parking brake on, despite the fact that a brake warning light is provided to indicate that condition.
It should be noted that the parking brake is applied only to the rear wheel brakes, if they are, in fact, used, and if they have not been ruined or worn out, as referred to above. Also, the "park" position of the transmission select lever, locks the transmission, not the brakes, and it may be, at least at times, not used when it should have been. The emergency service brake is required to apply only a portion of the service brake system.
A main object of this invention is to provide means in an automatic transmission motor vehicle to prevent forward creep of the vehicle when it is brought to a stop, as at an intersection, or in a traffic jam, with the motor running and the operator's feet are removed from the brake and accelerator pedals.
Another object of the invention is to provide such a device that locks the service brakes in the braking position in the above circumstances.
Another object of the invention is to provide such a device that will retain the service brake in the braking position even if the engine is turned off.
Still another object of the invention is to provide such a device that is automatically released when the accelerator pedal is depressed, as where it is desired to drive the vehicle when a traffic light turns to green, for example.
A further object of the invention is to provide such a device wherein the service brake lock is operative only in the last portion of service brake travel, just before the brake pedal is floored, for example, and wherein the locked service brake is released upon initial movement of the accelerator pedal from its free or engine idle position when the operator's foot is off the pedal.
Another object of the invention is to provide a means to retain the service brake in the brake-on position whenever the brake pedal is depressed to an essentially "floored" or full-on position, as where the vehicle is stopped on a hill.
Another object of the invention is to provide such a device or system having means to deactivate the exterior brake lights when leaving the vehicle with the service brake applied and to reactivate the brake light system upon reentering the vehicle, or to accomplish the same automatically.
A still further object of the invention is to provide such a device that can be manually deactivated, until manually activated, so that the vehicle can be used without the device when so desired.
A further object of the invention is to provide such an anti-creep system or device that is simple and inexpensive to manufacture and install, either at the factory for new vehicles, or as a do-it-yourself project for used vehicles.
These and other objects and advantages of the invention will become more apparent by reference to the following specification and the attached drawings.